1. Field of the Invention
The present invention relates to novel diphenylpyrrolylfuran derivatives. More specifically, the present invention relates to novel diphenylpyrrolylfuran derivatives useful as anti-inflammatory agents, anti-allergic agents, anti-platelet agents and the like.
2. Related Art
Since early 1970's, various non-steroidal anti-inflammatory agents, representative examples of such agents include indomethacin and ibuprofen, have been developed. The mechanisms of action of these drugs are mainly based on their inhibitory activities on the generation of prostaglandins by cyclooxygenases. However, these drugs selected from the view point of the inhibitory potency on the generation of prostaglandins have problems that they cannot achieve complete cure of intractable allergic and chronic inflammatory diseases [Hoshi, Iyaku Journal (Medicine and Drug Journal), 26, p. 933-937, 1990].
In general, it has been known that certain chemical mediators other than prostaglandins participate in inflammatory reactions. As such chemical mediators, bradykinin, serotonin, and complement activated products (C.sub.5a) as well as leukotriene, interleukins and the like have been known [Nakamura, Gendai Kagaku (Chemistry Today), 217, p. 38-45, 1989, Tokyo Kagaku Dojin]. Furthermore, it has also been known that, as a result of the inflammatory reactions, active oxygens produced by wondered leukocytes may deteriorate tissue damage, and that lipid peroxides produced are strong pain-inducing substances [Yagi, Kasankashishitsu to Shikkan (Lipid peroxides and Diseases), p. 210-217 (1981), Igaku Shoin].
Accordingly, developments of drugs have been strongly desired which inhibit the generation and activities of various inflammatory mediators as well as prostaglandins together with active oxygens.
The object of the present invention is to provide novel compounds having the activities described above.